1. Field of the Invention
The present invention relates to a substrate processing apparatus for processing substrates such as semiconductor wafers and glass substrates for liquid crystal displays (LCDs) and plasma display panels (PDPs), and to a substrate processing unit to be incorporated in such a substrate processing apparatus.
2. Description of Related Arts
In a semiconductor device production process, a semiconductor wafer (hereinafter referred to simply as "wafer") is subjected to a polishing process for polishing the surface thereof or the surface of a thin film formed thereon (hereinafter referred to generally as "wafer surface") with a slurry as an abrasive. In recent years, the CMP (chemical mechanical polishing) process has often been employed in which a physical polishing process using a slurry and a chemical polishing process utilizing a chemical reaction are performed in combination.
After the CMP process, the slurry and fragments of a film material polished off during the process are present on the wafer surface; therefore, the wafer should be further subjected to a cleaning process. A cleaning apparatus for cleaning a CMP-processed wafer typically has a construction as shown in FIG. 13.
The cleaning apparatus includes a submerged loader 1, a back-side brush-scrubbing unit 2, a front-side brush-scrubbing unit 3, a rinse/dry unit 4 and an unloader 5, which are linearly arranged within a single frame. Transportation robots 6, 7, 8, 9 for transferring wafers between the units on a wafer-by-wafer basis are provided between respective adjacent pairs of units.
The submerged loader 1 holds the CMP-processed wafers immersed in deionized water. The back-side brush-scrubbing unit 2 scrubs the back side of a wafer with a brush while supplying a chemical agent thereto. The front-side brush-scrubbing unit 3 scrubs the front side of the wafer that has been subjected to the back-side scrubbing process with a brush while supplying a chemical agent thereto. The rinse/dry unit 4 rinses the wafer that has been subjected to the front-side scrubbing process with water, and then spin-dries the wafer. The unloader 5 accommodates therein the wafer that has been subjected to the rinse/dry process.
FIG. 14 is a front view of the cleaning apparatus as seen from an arrow A in FIG. 13. The cleaning apparatus further includes a utility connection section 10 provided on a lower portion of a side wall thereof on the side of the arrow A for connecting necessary utilities thereto, and a display section 11 provided above the utility connection section 10 for displaying the flow rates and pressure levels of the utilities.
The utility connection section 10 includes a deionized water connection portion 12, a drain connection portion 13, a chemical agent connection portion 14, an exhaust connection portion 15 and an N.sub.2 gas connection portion 16. The deionized water connection portion 12 serves as a deionized water inlet for introducing deionized water into the apparatus from the outside to supply the deionized water into the submerged loader 1, the back-side brush-scrubbing unit 2, the front-side brush-scrubbing unit 3 and the rinse/dry unit 4. The drain connection portion 13 serves as a waste water outlet for discharging waste water from the submerged loader 1, the back-side brush-scrubbing unit 2, the front-side brush-scrubbing unit 3 and the rinse/dry unit 4 to the outside of the apparatus. The chemical agent connection portion 14 serves as a chemical agent inlet for introducing chemical agents into the apparatus from a chemical agent cabinet provided outside the apparatus to supply the chemical agents into the back-side brush-scrubbing unit 2 and the front-side brush-scrubbing unit 3. The exhaust connection portion 15 serves as an exhaust outlet for expelling an unnecessary gas from the back-side brush-scrubbing unit 2, the front-side brush-scrubbing unit 3 and the rinse/dry unit 4. The N.sub.2 gas connection portion 16 serves as a gas inlet for introducing N.sub.2 gas into the apparatus from the outside to supply the N.sub.2 gas into the rinse/dry unit 4.
The display section 11 has deionized water pressure display portions 17 for displaying the pressures of the deionized water supplied to the respective processing units, chemical agent flow rate display portions 18 for displaying the flow rates of the chemical agents supplied to the respective processing units, and an N.sub.2 gas flow rate and pressure display portion 19 for displaying the flow rate and pressure of the N.sub.2 gas supplied to the rinse/dry unit 4. These display portions 17, 18, 19 are separately provided on the plural processing units.
In the apparatus of the prior art, the utility connection section 10 is connected to the respective units via a plurality of branched pipes within the cleaning apparatus. Therefore, when the arrangement of the processing units is changed at the stage of the design of the apparatus, the pipe arrangement within the cleaning apparatus should be redesigned with a great effort. Further, when the arrangement of the processing units is changed after completion of assembly of the apparatus, the pipe connection within the cleaning apparatus should be re-established with a great effort. Thus, the troublesome operations for the redesign of the pipe arrangement and the re-establishment of the pipe connection impose limitations on the arrangement of the plural processing units. This hinders flexible arrangement of the plural processing units.
As described above, the respective display portions 17, 18, 19 are separately provided on the plural processing units, and are not necessarily located adjacent to the relevant processing units, so that checking of display information is difficult. In order to check an operation being performed in a particular processing unit, an operator has to check all the separately provided display portions 17, 18, 19. That is, the operator cannot check the display portions at a glance. Where a display portion which displays information required for checking the operation of the particular processing unit is located in a position remote from the processing unit, the operator cannot check the display information while visually checking the operation of the processing unit. Hence, the viewability of the display portions is not satisfactory in checking the operations of the processing units.